As an application for a projector, there is one type of application that performs correction processing for distortion and luminance unevenness of a projection screen. In addition, there is a multi-projection system that combines projection screens provided by a plurality of projectors into one projection screen, by joining the projection screens. In a case of the multi-projection system, there is one type of system that performs, in addition to the above-described correction processing for the distortion and the luminance unevenness of the projection screen, correction processing such as edge blending processing that makes a joint between a plurality of projection screens inconspicuous. As an example of performing the correction processing for the projection screen, there is a technique that captures an image of a projection screen using an imaging unit, creates correction data of the image on the basis of the captured image, and corrects an input image using the correction data. As an example of thus performing the correction processing for the projection screen, there is, for example, a technique described in PTL 1.